xntpd sendto (possible hack?)

[Lovell Mcilwain]

Hello all,

I just installed a logwatch on my machine and ran it for the first time 
just a few minutes ago.  It showed me something very interesting and it 
was the only thing in the logwatch log.  Just a bunch of the same 
entries.  The IP address varied but most of them looked like invalid 
arguments except for about 3 of them that didn't.  See below:

--------------------- XNTPD Begin ------------------------ 

 **Unmatched Entries**
.....
 sendto(80.190.233.67): Invalid argument
 synchronized to 80.190.233.67, stratum 2
 synchronized to 80.33.117.152, stratum 3
 sendto(80.190.233.67): Invalid argument
.....
 ---------------------- XNTPD End -----------------------

Does anyone know what this means or can this possibly mean that my system has been hacked?